为了系统研究强力旋压成形纳米/超细晶筒形件过程中纳米/超细晶的形成机理，以具有高层错能的体心立方金属20 钢为研究对象，首先通过分析旋压样件变形区剖面和表面的扇形塑性流动场来定性和定量解析强力错距旋压过程中金属流动的机理，然后采用金相分析技术和TEM 技术研究了F + P 钢在受强力旋压而剧烈剪切变形时的晶粒形态．结果显示: 与其他强烈塑性变形方法类似，强力旋压过程中随着工件壁厚减薄率的增加，材料内部等轴初晶逐渐沿轴向被拉长，形成具有一定取向的冷变形织构，在随后的580℃ × 1 h 的退火过程中生成了大小约为600 nm 的等轴细晶．

In order to explore the formation mechanism of nano /ultrafine grains during the power spinning of nano /ultrafine grained cylindrical parts,the body-centered cubic steel 20 with high stacking fault energy was taken as theresearch objective,and the metal flow mechanism during the strong stagger spinning was qualitatively and quantitativelyinvestigated by analyzing the fan-shaped plastic flow field in the section and surface of the deformation area ofsteel 20.Then,the evolution of grain morphology of steel F + P during the severe shear deformation caused by powerspinning was discussed by means of metallographic analysis and TEM.The results show that,like other severeplastic deformation technologies,power spinning results in the stretching of isometric crystals in axial direction withthe increasing thinning ratio of wall thickness,which helps to form cold deformation texture with certain orientationdegree and to further generate tiny isometric ferritic 600 nm grains during the annealing at 580℃ for 1 hour.